You probably need to see my own explanation of negative exponents. Why don't you take a look at my own website by doing a "Bing" search for my last name "Rapalje". Look for my website "Rapalje Homepage" near the top of the search list. On my webpage, look for "Basic, Intermediate and College Algebra: One Step at a Time." Select "Basic Algebra" and look in "Chapter 2" for "Section 2.13 Laws of Exponents: Zero and Negative Exponents." This is my own non-traditional explanation that my own students ALL found easier to understand than the one given in traditional textbooks. See also the corresponding section in my "MATH IN LIVING COLOR" pages in which I solved a lot of these types of problems in COLOR!!
R^2
Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus
